Road surfacing apparatus

ABSTRACT

The obliquely disposed cutters of a road surface planing machine are caused to vibrate during the planing operation, so that the cutting edge of the blade is alternatingly advanced and retracted, to provide a percussive stone-splitting action and thereby produce a more accurate and smoother planed surface. Camber changes are effected by mounting each cutter on a support structure which is mounted on a rigid frame member of the machine chassis for adjustment about a pivot axis extending obliquely to the cutting edge, and preferably longitudinally of the vehicle.

United States Patent 1 Housego 1 May 15,1973

[54] ROAD SURFACING APPARATUS [76] Inventor: Leonard J. Housego, 134, Craddocks Ave., Ashtead, Surrey, England [22] Filed: Nov. 16, 1971 [21] Appl. No.: 199,324

Related US. Application Data [63] Continuation of Ser. No. 11,146, Feb. 13, 1970.

[52] US. Cl ..299/37, 37/D1G. 18, 172/40,

[51] Int. Cl ..E0lc 23/09 [58] Field of Search ..299/26, 37, 14; 37/DIG. 18; 172/40 [5 6] References Cited UNITED STATES PATENTS 2,690,902 10/1954 Ream ..37/D1G.l8

2,970,392 2/1961 Perkins et a1 172/40 3,251,628 5/1966 Wrockloff ..299/37 X 3,478,450 11/1969 Cunningham ..172/40 X Primary ExaminerErnest R. Purser Attorney- Lawrence E. Loubscher [57] ABSTRACT The obliquely disposed cutters of a road surface planing machine are caused to vibrate during the planing operation, so that the cutting edge of the blade is alternatingly advanced and retracted, to provide a percussive stone-splitting action and thereby produce a more accurate and smoother planed surface.

Camber changes are effected by mounting each cutter on a support structure which is mounted on a rigid frame member of the machine chassis for adjustment about a pivot axis extending obliquely to the cutting edge, and preferably longitudinally of the vehicle.

8 Claims, 4 Drawing Figures PATENTEUIWI 51m 3,733,105

SHEET 1 [IF 4 Leonard T- Housazio INVENTOR z rna/4114M mix/1m PATEr-II'EWI 51975 3,733,105

SHEET 3 [1F 4 Leona/VJ I, Howse ov INVENTOR w 16mm ATTORNEY PATENTED m 1 5 W s; 733, 105

SHEU l 0F 4 gonad f- H0 4 $6 550 INVENTOR ATTORNEY 1 ROAD sURFAciNG APPARATUS This is a continuation application of application Ser. No. 11,146 filed Feb. 13, 1970.

This invention relates to road planing machines for use in planing, or reducing in datum height, a road or other metalled surface intended to carry traffic. Such machines conventionally comprise a chassis carried on wheels, or other means (such as caterpillar tracks) which allow it to travel over a surface to be treated and employ one or more knife-like, cutting, or planing members, each of which has a cutting edge disposed obliquely to the direction of travel of the machine. In conventional apparatus for this purpose the cutting members are rigidly fixed, relative to the chassis, in their operative positions and in use they tend to tear at the surface on which they are working and to remove individual stones bodily. The planing operation is rather slow and, for the reason just stated, unsatisfactory in that the planed surface is very rough with many cavities and depressions.

In accordance with one feature of the present invention, the (or each) cutting member is continuously vibrated in operation, so as alternately to advance and retract the cutting edge thereof, thereby combining an oblique slicing action with the principle of percussive stone breaking.

Trials have proved that this percussive action is highly effective in splitting even the hardest stones at substantially the level of the cut, so that the planed surface is very much smoother, and more accurately positioned than can be obtained by the use of fixed cutters, and the operation can be speeded up very substantially, thereby offering great economies in the preparation of roads for re-surfacing.

Another disadvantage of the known machines arises out of the fact that, for the purpose of varying the inclination of the cutting edges, to provide different angles of camber, each cutter blade pivots at a point perpendicular to the cutting edge, but in practice it has been found that this pivotal connection is a point of considerable weakness and is liable to failure by way of seizing or breakage under the very high loads to which the cutter blade is subjected in use.

The present invention further provides an improved arrangement for mounting and inclining the cutter blade and in accordance with a further feature of the invention, the (or each) cutter blade is carried by a support structure in turn pivotally mounted on a rigid frame member (preferably tubular) of the chassis of the machine, for pivotal adjustment about a generally horizontal pivot axis extending obliquely to the cutting edge of the cutter blade.

With this arrangement, it becomes possible to provide a very strong pivotal connection of large diameter and bearing length. Preferably, the chassis frame member extends longitudinally of the chassis (i.e., parallel with the direction of movement) so that principle cutting reaction forces transmitted back through the cutting and support members are applied to the frame member as a couple acting about a horizontal axis transverse to the frame member. Reaction forces tending to rotate the cutter and support members about the frame member axis are readily resisted by a stabilizing reactive force applied to the support member at a suit able distance from the frame member axis, roughly equal to the distance from the frame member axis of the cutting member. Thus, by suitable proportioning of the parts the cutter support and reaction structure can be made extremely rigid, and yet a fine degree of control of cambering angle is obtainable.

In a preferred embodiment, a chassis carries two, four or more cutter blades, each mounted on its own support member in the manner described above, the cutter blades being arranged in opposed pairs of members on opposite sides of the chassis, usually disposed inwardly and rearwardly of the direction of forward movement of the chassis.

The chassis may form a self-contained unit which is propelled in use by an automative unit or may form an integral part of an automative vehicle. Provision may also be made for mounting a road surface heating unit ahead of or on the chassis.

The individual cutter blades are preferably mounted for vertical adjustment relative to their support members.

These and other features of the invention will appear from the following description, given by way of example, of a road planing machine in accordance with the invention and illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of a fully integrated automative road planing machine; and

FIGS. 2, 3 and 4 are a rear elevation, side elevation and top plan view, respectively, of a single cutter assembly and mounting unit of the machine of FIG. 1.

The road planing machine shown in FIG. 1 takes the form of an integrated automative vehicle comprising a driving unit 10 and a cutter carrying chassis 11. The driving unit includes an operators cabin, and two oil engine units powering respectively an air compressor and an hydraulic pump, either unit being employed also as a source of automative power. It also carries an elevator 12 for raising loosened materials from road level and delivery to a discharge conveyor 13 to carry such materials rearwardly of the machine to a following truck or other receptacle. This conveyor may be fitted with a movable carrier carrying a scraper shoe, movable longitudinally along the top face of the conveyor belt for discharging the spoil evenly throughout the length of the vehicle body or other receptacle. The elevator and conveyor are each pivotally mounted for movement between the operating position shown and an inoperative position in which elevator is lowered to a substantially horizontal position and the conveyor to a generally vertical position.

The chassis 11 comprises a rigid structure having two main frame members in the form of two horizontal tubes 14 extending longitudinally of the machine throughout the length thereof. The tubes may, for example, be approximately 15 inches (38cm) outside diameter.

Mounted on the chassis unit are four cutter mounting units 16 (which are described in detail below) each having a knife-like cutting member or blade 21 having its cutting edge disposed generally horizontally and obliquely to the direction of travel of the machine. The cutters are arranged in two pairs of opposed cutters, on opposite sides of the vehicle and each inclined inwardly and rearwardly to the direction of travel. The leading pair of cutters are offset inwardly from the trailing pair in a wind row configuration, so that materials loosened by the cutter are guided towards the center-line of the machine, where they are picked up from the road surface by the elevator 12. Brushes 17 for sweeping loose materials towards the center of the machine are automatically reciprocated laterally of the machine by hydraulic cylinders 17A.

One cutter mounting unit is shown in detail in FIGS. 2, 3 and 4 of the drawings, and includes a horizontally extending steel cutter blade 21 mounted in a rigid bracket 22 fast at the lower end of a slide 23 mounted for vertical movement in a guideway formed in a rigid support member 24. The slide 23 is formed by a heavy I-beam section and is guided for vertical movement by roller bearings 33 carried by the support member 24. The roller bearings 33 are mounted in pairs, each pair being held in place by a spring clip 34 which urges the rollers through slots in the adjacent portion of the support member into firm, rolling engagement with the adjacent face of the slide 23, which has limited lateral clearance from the support member.

These rollers facilitate raising and lowering of the slide 23, but when the cutters are under load, the spring clips 34 yield sufficiently to allow the slide to bear directly against the support member.

Mounted at the top of the support member is a double acting hydraulic cylinder 25, the ram of which is connected to the slide 23 for moving the slide vertically, relative to the support member 24. An adjustable stop for limiting downward movement of the slide is formed by an eccentric 26 mounted on a spindle 27 extending through and journalled in the support member 24. The eccentric co-operates with a vertically elongated opening 23A in the slide 23 and is shown in FIGS. 2 and 3 in an extreme position in which it acts to assist downward movement of the slide at a position of minimum depth of cut. The limit of downward movement can be progressively lowered by rotating the spindle and eccentric through 180 by means of a hand wheel 28 carrying a locking bolt 29 engageable in any of a series of holes around a locking plate 30. With this arrangement, a depth of cut setting can be retained, and the slide raised (retracted) and returned to this setting as desired, for example when some obstruction, such as a manhole cover, is to be cleared.

The support member 24 is journalled on the adjacent tubular frame member 14, for pivotal movement about the longitudinal axis thereof under the action of an hy-' draulic cylinder 31 mounted on the chassis and having its ram connected to the support member at a distance from the pivotal axis roughly equal to the distance of the cutter blade 21 from the same axis.

It will be appreciated that, since the pivotal axis of the support member is oblique to the edge of the cutter blade 21, adjustment of the support member about its pivotal axis will vary the inclination of the horizontal ground level of the cutter blade edge, thus affording camber adjustment of the cutter blade. The degree of adjustment is controlled by pilot operated check valves in the lines to the cylinder 31. The arrangement in the illustrated embodiment is such that the camber is continuously variable between a 9 positive camber to a 4% negative camber. Drag loads acting on the cutter in operation will tend to tilt the cutter and support member in an anti-clockwise direction as viewed in FIG. 3, about an horizontal axis perpendicular to the frame member 14, to which a corresponding couple is applied. However, this reaction is readily taken by the frame member due to its strength in bending and the wide bearing length available. A pivotal connection of such properties and strength cannot be obtained in conventional designs in which the cutter blade itself is pivoted about an axis perpendicular to the blades. Laterally resolved reactor forces tending to rotate the cutter and support member about the frame member are, of course, taken by the hydraulic cylinder 31.

As mentioned above, the cutter blades 21 are mounted in rigid brackets 22. Each cutter blade is of substantially L-shaped cross-section, having at its horizontal forward edge sharpened to a cutting edge 41. This cutting edge may, if desired, be formed as a separate, replaceable member. At two points along its length, the cutter blade has upwardly extended lugs 42 formed at their upper ends with bosses which are connected to the bracket 22 by horizontal pivots 43, parallel with the edge 41.

Secured to the rear of the cutter blade 21 is a vibrator unit 44 of known type comprising a motor driven electrically, hydraulically or pneumatically and having a rotary shaft carrying an eccentrically disposed weight. The unit 44 is depicted in the drawing as having its axis disposed horizontally, but could alternatively be mounted in a vertical attitude. Since the motor is offset from the axis of the pivots 43, it will be appreciated that the vibrator unit will, in operation, apply alternate impulses to the cutter blade in the forward and reverse directions, thus advancing and retracting the cutting edge 41. These oscillatory movements, in both directions, of the cutter blade are damped by springs acting between the cutter blade and the bracket 22. The springs for damping forward movement are shown at 46, and the springs for damping rearward movement, not shown, may be similarly arranged. More particularly, each of the springs 46 is a coil compression spring mounted on a bolt 47 extending through the rear wall of bracket 22 and threaded into the cutter blade, so that the preloading of the spring can be adjusted by screwing the bolt further into or out of the cutter blade. In operation, these springs 46 are compressed during the forward swing of the cutter blade, damping their movement, and then assist in returning the blade rearwardly.

I claim:

1. An apparatus for planing a road surface, comprismg:

a. chassis means (11) for moving in a given direction of travel over the road surface to be planed, said chassis means including at least one frame member (14) extending longitudinally of the road planing apparatus;

b. cutter blade means (21) for removing material from the road surface, including at least one cutting edge (41) disposed generally horizontally and obliquely to the direction of travel of said apparatus;

c. bracket means (22) for mounting said cutter blade means for pivotal movement about an axis parallel to the direction of said cutting edge;

d. vibratory means (44) for alternately advancing and retracting said cutting edge in a direction transverse to its length;

e. support means (24) for supporting said cutting edge comprising front and rear generally vertical walls;

f. slide means (23) for vertical movement between said front and rear walls, said bracket means being attached to one end of said slide means for vertical movement therewith; and

g. bearing means for journalling said support means to said frame member for pivotal movement about the longitudinal axis of said frame member, whereby the principle cutting reaction forces transmitted back through said bracket means, said slide means, said support means and said bearing means are applied to said frame member as a couple acting about a horizontal axis transverse to said frame member.

2. Apparatus as claimed in claim 1, wherein said vibratory means comprises an eccentrically weighted, power driven rotary shaft, and means mounting said vibratory means directly on said cutter blade means.

3. Apparatus as claimed in claim 1, comprising coil compression spring means acting on said cutter blade means for controlling oscillatory movements thereof about said parallel axis.

4. The apparatus of claim 1, comprising power operated means for raising and lowering said slide means, and adjustable stop means for pre-setting the extreme lower, operative position of said slide means.

5. The apparatus of claim 1, wherein said slide means is mounted with running clearance between said slide means and said front and rear walls, and further comprising spring loaded roller means acting between said slide means and said support member for facilitating vertical adjustment of said slide means and for yielding to permit said slide means to take up said running clearance and be directly supported by said front and rear walls when the apparatus is in operation.

6. An apparatus for planing a road surface, comprismg:

a. chassis means 11) for moving in a given direction of travel over the road surface to be planed, said chassis means including two tubular frame members (14) extending horizontally and longitudinally of the road planing apparatus, said tubular members having a circular cross section approximately 15 inches in diameter;

b. a plurality of cutting units (16) mounted on the said two tubular frame members, an equal number of units being mounted on each frame member, each cutter unit comprising:

2. a cutter blade (21) having a cutting edge (41) disposed generally horizontally,

2. bracket means (22) for supporting said cutter blade for pivotal movement about an axis parallel to the direction of the cutting edge,

3. vibrating means (44) for alternately advancing and retracting said cutting edge about said parallel axis,

4. a rigid support member (24) comprising front and rear generally vertical walls,

5. slide means (23) for vertical movement between said front and rear walls, said slide means comprising an l-beam which has limited lateral clearance from said front and rear walls and said bracket means being attached to one end of said slide means for vertical movement therewith, 6. roller means (33) for reducing friction between said slide means and said front and rear walls,

said roller means being yieldably mounted to permit said slide means to take up said lateral clearance whereby said slide means may be directly supported by said front and rear walls when said apparatus is in operation,

7. bearing means for journalling said support member to one of the said frame members for pivotal movement about the longitudinal axis of said frame member, said bearing means having a bearing length comparable to the diameter of said tubular member, whereby the principle cutting reaction forces transmitted back through said bracket means, said slide means, said rigid support and said bearing means are applied to said associated frame member as a couple acting about a horizontal axis transverse to said frame member; and

c. said cutter blades being oriented inwardly toward the centerline of the apparatus and rearwardly to the direction of travel of said apparatus whereby materials loosened by the cutter blade are guided toward the centerline of the apparatus.

7. Road planing apparatus comprising:

a. a chassis (11) adapted for longitudinal transport over a road surface to be planed;

b. a cutter blade (21) having a linear cutting edge c. means connecting said cutter blade with said chassis at a first position at which said cutting edge is horizontal and arranged at an oblique angle relative to the longitudinal axis of said chassis, said connecting means including:

1. vertical support means (24) pivotally connected with said frame for pivotal movement about a first pivot axis (14) obliquely arranged relative to said cutting edge;

2. a rigid bracket (22) connected with the lower end of said vertical support means; and

3. means pivotally connecting said cutter blade with said bracket for pivotal movement about a second pivot axis (43) parallel with said cutting edge;

d. camber adjusting means (31) for pivoting said support means about said first pivot axis to place said cutter blade at a second position at which the cutting edge thereof is inclined at a slight oblique camber angle relative to the road surface to be planed; and

e. vibrator means (44) for vibrating said cutter blade about said second pivot axis relative to said bracket.

8. Apparatus as defined in claim 7, wherein said first pivot axis extends longitudinally of the chassis, and further including slide means connecting said bracket for sliding movement longitudinally of said support means for varying the spacing distance between said first and second pivot axes, whereby the height of said cutting edge may be adjusted relative to the road surface to be planed. 

1. An apparatus for planing a road surface, comprising: a. chassis means (11) for moving in a given direction of travel over the road surface to be planed, said chassis means including at least one frame member (14) extending longitudinally of the road planing apparatus; b. cutter blade means (21) for removing material from the road surface, including at least one cutting edge (41) disposed generally horizontally and obliquely to the direction of travel of said apparatus; c. bracket means (22) for mounting said cutter blade means for pivotal movement about an axis parallel to the direction of said cutting edge; d. vibratory means (44) for alternately advancing and retracting said cutting edge in a direction transverse to its length; e. support means (24) for supporting said cutting edge comprising front and rear generally vertical walls; f. slide means (23) for vertical movement between said front and rear walls, said bracket means being attached to one end of said slide means for vertical movement therewith; and g. bearing means for journalling said support means to said frame member for pivotal movement about the longitudinal axis of said frame member, whereby the principle cutting reaction forces transmitted back through said bracket means, said slide means, said support means and said bearing means are applied to said frame member as a couple acting about a horizontal axis transverse to said frame member.
 2. Apparatus as claimed in claim 1, wherein said vibratory means comprises an eccentrically weighted, power driven rotary shaft, and means mounting said vibratory means directly on said cutter blade means.
 2. a rigid bracket (22) connected with the lower end of said vertical support means; and
 2. bracket means (22) for supporting said cutter blade for pivotal movement about an axis parallel to the direction of the cutting edge,
 2. a cutter blade (21) having a cutting edge (41) disposed generally horizontally,
 3. means pivotally connecting said cutter blade with said bracket for pivotal movement about a second pivot axis (43) parallel with said cutting edge; d. camber adjusting means (31) for pivoting said support means about said first pivot axis to place said cutter blade at a second position at which the cutting edge thereof is inclined at a slight oblique camber angle relative to the road surface to be planed; and e. vibrator means (44) for vibrating said cutter blade about said second pivot axis relative to said bracket.
 3. vibrating means (44) for alternately advancing and retracting said cutting edge about said parallel axis,
 3. Apparatus as claimed in claim 1, comprising coil compression spring means acting on said cutter blade means for controlling oscillatory movements thereof about said parallel axis.
 4. The apparatus of claim 1, comprising power operated means for raising and lowering said slide means, and adjustable stop means for pre-setting the extreme lower, operative position of said slide means.
 4. a rigid support member (24) comprising front and rear generally vertical walls,
 5. slide means (23) for vertical movement between said front and rear walls, said slide means comprising an I-beam which has limited lateral clearance from said front and rear walls and said bracket means being attached to one end of said slide means for vertical movement therewith,
 6. roller means (33) for reducing friction between said slide means and said front and rear walls, said roller means being yieldably mounted to permit said slide means to take up said lateral clearance whereby said slide means may be directly supported by said front and rear walls when said apparatus is in operation,
 5. The apparatus of claim 1, wherein said slide means is mounted with running clearance between said slide means and said front and rear walls, and further comprising spring loaded roller means acting between said slide means and said support member for facilitating vertical adjustment of said slide means anD for yielding to permit said slide means to take up said running clearance and be directly supported by said front and rear walls when the apparatus is in operation.
 6. An apparatus for planing a road surface, comprising: a. chassis means (11) for moving in a given direction of travel over the road surface to be planed, said chassis means including two tubular frame members (14) extending horizontally and longitudinally of the road planing apparatus, said tubular members having a circular cross section approximately 15 inches in diameter; b. a plurality of cutting units (16) mounted on the said two tubular frame members, an equal number of units being mounted on each frame member, each cutter unit comprising:
 7. Road planing apparatus comprising: a. a chassis (11) adapted for longitudinal transport over a road surface to be planed; b. a cutter blade (21) having a linear cutting edge (41); c. means connecting said cutter blade with said chassis at a first position at which said cutting edge is horizontal and arranged at an oblique angle relative to the longitudinal axis of said chassis, said connecting means including:
 7. bearing means for journalling said support member to one of the said frame members for pivotal movement about the longitudinal axis of said frame member, said bearing means having a bearing length comparable to the diameter of said tubular member, whereby the principle cutting reaction forces transmitted back through said bracket means, said slide means, said rigid support and said bearing means are applied to said associated frame member as a couple acting about a horizontal axis transverse to said frame member; and c. said cutter blades being oriented inwardly toward the centerline of the apparatus and rearwardly to the direction of travel of said apparatus whereby materials loosened by the cutter blade are guided toward the centerline of the apparatus.
 8. Apparatus as defined in claim 7, wherein said first pivot axis extends longitudinally of the chassis, and further including slide means connecting said bracket for sliding movement longitudinally of said support means for varying the spacing distance between said first and second pivot axes, whereby the height of said cutting edge may be adjusted relative to the road surface to be planed. 